an interesting expereiment to see if you are a synesthete (may not work for all synesthests unless you change what is tested IYSWIM')
'Read a list of random numbers between 0 and 9 at a rate of about one every 3 seconds. For example: 7, 9, 4, 0, 3, 8, 2, 5, 1, 6.
After each number is read, ask people to write down the number and what COLOR that they associate with each number.
Collect the answers. These will be called "Answers #1".
Two to three weeks later, repeat the experiment, but change the order of the numbers. For example: 3, 6, 5, 9, 4, 1, 7, 0, 5, 2, 8.
Collect the answers. These will be called "Answers #2".
Compare Answers #1 with Answers #2. A person with synesthesia will have all or most of the same number-color pairs on both Answers #1 and Answers #2.
This experiment can also be done using letters instead of numbers. '